How to use the summer.config.DevConfig function in summer

class TestConfig(Config):
    SITE_NAME = 'Test'
    SUBTITLE = '「东张西望 一无所长」'
    DOMAIN = 'http://gaowhen.dev/'
    DATABASE_URI = os.path.join(basedir, 'data-test.db')


class ProductConfig(Config):
    SITE_NAME = 'GaoWhen高H温'
    SUBTITLE = '「文不能测字 武不能防身」'
    DOMAIN = 'http://gaowhen.com/'
    DATABASE_URI = os.path.join(basedir, 'blog.db')


config = dict(
    dev=DevConfig,
    test=TestConfig,
    product=ProductConfig
)